Quillgin is the main antagonist of Regular Show's episode "The Christmas Special". He was a former scientist at Santa Claus' Toy Factory who later betrayed him for destroy the Christmas Day.
As the lead toy designer of Santa Claus, he spent his life working on a present that will give children anything they were anticipated for. He used dark magic as a key component. In testing the box, people turned evil, so Santa ordered his elves to destroy Quillgin's life's work, leading to Quillgin's breakout.
During the night of the Christmas Day, Quillgin assaulted the Toy Hangar and stole his creation for destroy the Christmas Day, and also stole Santa's Sled. However, Santa appeared in scene and was apparently killed by Quillgin despite Rodolphus the Reindeer's help, but he fell from the sled along the present, for Quillgin's angry.
After discovered that Mordecai, Rigby and the other employees of the Park had his present, Quillgin and his elves allies infiltrated into East Pines and knocked Gene's Forest Rangers, but Gene helped the Park's employees to escape to the Cave in that where is the lava pit that can destroy Quillgin's creation. Once inside the Cave, Quillgin and his henchmen attacked the Park's employees in the ice bridge, but Benson lost the Pinball on purpose, leading to the destruction of the ice brigde, causing the demise of Quillgin's henchmen.
However, Quillgin used a emergency stairs from the Cave to reach the Park's employees and threatened to kill them if they didn't gave to him the present. Despite Santa's help, Mordecai decided to sacrifice himself and push Quillgin into the lava pit while him was formulating his wish of destroy the Christmas. However, Rigby decided to save his friend and pulled himself into the pit. When he reached Mordecai and Quillgin, Rigby fought Quillgin in the air and finally, he wished with the present a flyign double skate board, that he and Mordecai used to reach out of the pit and be safe. However, Quillgin tried to reach his creation in his last moments for finally destroy the Christmas, but finally, he fell into the lava along his present, killing him and destroying his present.
- His desing is similar to Hunk's design of Resident Evil.